653 research outputs found
On the difference-to-sum power ratio of speech and wind noise based on the Corcos model
The difference-to-sum power ratio was proposed and used to suppress wind
noise under specific acoustic conditions. In this contribution, a general
formulation of the difference-to-sum power ratio associated with a mixture of
speech and wind noise is proposed and analyzed. In particular, it is assumed
that the complex coherence of convective turbulence can be modelled by the
Corcos model. In contrast to the work in which the power ratio was first
presented, the employed Corcos model holds for every possible air stream
direction and takes into account the lateral coherence decay rate. The obtained
expression is subsequently validated with real data for a dual microphone
set-up. Finally, the difference-to- sum power ratio is exploited as a spatial
feature to indicate the frame-wise presence of wind noise, obtaining improved
detection performance when compared to an existing multi-channel wind noise
detection approach.Comment: 5 pages, 3 figures, IEEE-ICSEE Eilat-Israel conference (special
session
Multi-scale aggregation of phase information for reducing computational cost of CNN based DOA estimation
In a recent work on direction-of-arrival (DOA) estimation of multiple
speakers with convolutional neural networks (CNNs), the phase component of
short-time Fourier transform (STFT) coefficients of the microphone signal is
given as input and small filters are used to learn the phase relations between
neighboring microphones. Due to this chosen filter size, convolution
layers are required to achieve the best performance for a microphone array with
M microphones. For arrays with large number of microphones, this requirement
leads to a high computational cost making the method practically infeasible. In
this work, we propose to use systematic dilations of the convolution filters in
each of the convolution layers of the previously proposed CNN for expansion of
the receptive field of the filters to reduce the computational cost of the
method. Different strategies for expansion of the receptive field of the
filters for a specific microphone array are explored. With experimental
analysis of the different strategies, it is shown that an aggressive expansion
strategy results in a considerable reduction in computational cost while a
relatively gradual expansion of the receptive field exhibits the best DOA
estimation performance along with reduction in the computational cost.Comment: arXiv admin note: text overlap with arXiv:1807.1172
Modal Decomposition of Feedback Delay Networks
Feedback delay networks (FDNs) belong to a general class of recursive filters
which are widely used in sound synthesis and physical modeling applications. We
present a numerical technique to compute the modal decomposition of the FDN
transfer function. The proposed pole finding algorithm is based on the
Ehrlich-Aberth iteration for matrix polynomials and has improved computational
performance of up to three orders of magnitude compared to a scalar polynomial
root finder. We demonstrate how explicit knowledge of the FDN's modal behavior
facilitates analysis and improvements for artificial reverberation. The
statistical distribution of mode frequency and residue magnitudes demonstrate
that relatively few modes contribute a large portion of impulse response
energy
Eccentricities of Double Neutron Star Binaries
Recent pulsar surveys have increased the number of observed double neutron
stars (DNS) in our galaxy enough so that observable trends in their properties
are starting to emerge. In particular, it has been noted that the majority of
DNS have eccentricities less than 0.3, which are surprisingly low for binaries
that survive a supernova explosion that we believe imparts a significant kick
to the neutron star. To investigate this trend, we generate many different
theoretical distributions of DNS eccentricities using Monte Carlo population
synthesis methods. We determine which eccentricity distributions are most
consistent with the observed sample of DNS binaries. In agreement with
Chaurasia & Bailes (2005), assuming all double neutron stars are equally as
probable to be discovered as binary pulsars, we find that highly eccentric,
coalescing DNS are less likely to be observed because of their accelerated
orbital evolution due to gravitational wave emission and possible early
mergers. Based on our results for coalescing DNS, we also find that models with
vanishingly or moderately small kicks (sigma < about 50 km/s) are inconsistent
with the current observed sample of such DNS. We discuss the implications of
our conclusions for DNS merger rate estimates of interest to ground-based
gravitational-wave interferometers. We find that, although orbital evolution
due to gravitational radiation affects the eccentricity distribution of the
observed sample, the associated upwards correction factor to merger rate
estimates is rather small (typically 10-40%).Comment: 9 pages, 8 figures, accepted by ApJ. Figures reduced and some content
changed, references adde
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